Lasers at the cutting edge of science

From the editors and reporters of Scientific American , this blog delivers commentary, opinion and analysis on the latest developments in science and technology and their influence on society and policy. From reasoned arguments and cultural critiques to personal and skeptical takes on interesting science news, you'll find a wide range of scientifically relevant insights here. Follow on Twitter @sciam.

Larry Greenemeier is the associate editor of technology for Scientific American, covering a variety of tech-related topics, including biotech, computers, military tech, nanotech and robots. Follow on Twitter @lggreenemeier.

“When you flash a laser for the first time…it’s like you’ve created something magical.” Tom Baer, executive director of the Stanford Photonics Research Center, said this to me recently when I asked him why he’s spent the past three decades both studying and developing the technology.

Aesthetics aside, Baer says he’s seeing a “renaissance” in laser technology in recent years. Use of the that word to describe anything other than the cultural movement of the late Middle Ages gives me pause, but Baer readily provided several examples of cutting-edge research enabled by lasers, including the following:

The National Ignition Facility (NIF) has, since it opened at Lawrence Livermore National Laboratory in May 2009, begun operating an array of lasers that are 100 times more powerful than any that have existed before in order to recreate the same fusion energy process that fuels the stars in our galaxy. NIF’s experiments focus the energy of 192 giant laser beams on a BB-sized target filled with hydrogen fuel, with the goal of fusing the hydrogen atoms’ nuclei and producing a net energy gain, according to Baer. NIF is itself claiming that it expects to be the first facility to achieve fusion ignition and energy gain in a laboratory setting. “The National Ignition Facility is pushing forward the whole area of high-powered lasers, using solid state lasers based on ceramics,” Baer said.

Lasers are also enabling a new class of artificially engineered materials called “metamaterials” that gain different properties based on their structure rather their composition, he told me. An example of this is the use of lasers to create tiny holes in polymer or glass fibers. “Instead of creating a uniform fiber-optic fiber, you have a holey fiber with different optical characteristics,” Baer said. “It’s not just glass, it’s a combination of air and glass, so it can shift the properties of glass fibers. These are becoming integrated in the next generation of telecommunications.” Whereas fiber-optic cables generally have to be straight to carry a strong signal, the flexibility of these new fiber optic lines makes them easier to work with. “You could use a staple gun to mount fiber lines in a home or office installation” without degrading the signal, he added.

Lasers are also being used at the forefront of neuroscience, Baer said, to help researchers understand how the brain processes information, something that would improve not just medicine but the development of artificial intelligence. “We have lacked the tools to date to make measurements of the brain’s organic circuits,” he added. “These are very basic questions that we want to understand.”

The approach, called optogenetics, involves using lasers and microscopy to excite and study different areas of fruit fly brains. A fruit fly has a brain the size of a grain of salt, but it is a complex brain that has some of the same basic circuit elements as the human brain, Baer said, adding that lasers are used on “alert, behaving animals such as fruit flies” that have been genetically engineered to create dyes when neurons are fired. This allows researchers to observe in real time many neurons at once as they process information.

The work raises some ethical issues that need to be explored, particularly as its application moves from insects to other animals, he acknowledged, but it represents a “phenomenal change in our ability to observe and model these processes. We will have working models of small animals in five to 10 years (not 50 years), and the work is all powered by lasers.”